[Surgical treatment of malignant tumors of the paranasal sinuses with involvement of the base of the skull].

After 18 years of close cooperation between ORL and neurosurgery in the treatment of the base of the skull, the authors present their surgical conception and technique for the treatment of malignant tumors of the paranasal sinuses involving the base of the skull. Three basically different surgical procedures are possible: 1. Extracranial partial resection of the anterior base of the skull sparing the contents of the orbit. 2. Radical revision of superior maxilla, ethmoid bone, and base of the skull including exenteratio orbitae. 3. Combined intra-extracranial approach. An interdisciplinary cooperation and the combination of macro- and microsurgery will be more successful with respect to survival chances, functional and esthetic results.